Xerographic fixing device



J1me 1966 F. w. HUDSON 3,

XEROGRAPHIC FIXING DEVICE Filed Dec. 23, 1963 5 Sheets-Sheet 1 INVENTOR. FREDERICK W. HUDSGN ATTORNE Y June 14, 1966 F. w. HUDSON XEROGRAPHIC FIXING DEVICE 5 Sheets-Sheet 2 Filed Dec. 23, 1963 N n OD T mw r E A wmt v K J c m w E 0 y E LY/ F B 1 S WWW/NW kb a .\Q NQQ URN L HQ June 14, 1966 F. w. HUDSON XEROGRAPHIC FIXING DEVICE 5 Sheets-Sheet 5 Filed Dec. 25, 1963 INVENTOR. REDERICK W. HUDSON BY jfiM/M ATTORNEY June 14, 1966 F. w. HUDSON XEROGRAPHIC FIXING DEVICE 5 Sheets-Sheet 4 Filed Dec. 23, 1963 in V bPx m; mvm 86 M J N: m: 4: w: nmm N3 3m 8m mm Rm Rm mum \wm N8 www 11 a an ii Tm no 3m I 1 I- a 1 wa ,LHHJWW. b8 :u I 313%? :m mom IN VENTOR. RICK W. HUDSON F EDE NQQ ATTORNEY June 14, 1966 F. w. HUDSON XEROGRAPHIC FIXING DEVICE 5 Sheets-Sheet 5 Filed Dec. 25, 1963 N n O N mm m New n. H 5% N MQQJ A NW raw M m w a M fi m u H Z R was F m a:

Gm \Bm .v v3 mum k .25: wk. 2 -u. 8mm 1 $3 Q8 4%. :1

3,256,002 XEROGRAPHIC FIXING DEVICE Frederick W. Hudson, West Henrietta, N.Y., assignor to.

Xerox Corporation, Rochester, N.Y., a corporation of New York Filed Dec. 23, 1963, Ser; No. 332,420 2 Claims. (Cl. 263-3) heated-roll fusing device. Although the invention is considered to have general application, it is particularly useful in the field of xerography and has an important application in the fusing of resinous powder images produoed by electrophotography or xerography onto sheets of paper and the like to which the powder images have been transferred after they have been formed by deposition of powder on an electrostatic latent image. Therefare, for convenience of illustration, the invention is described with reference to its use as a heat, for xerographic powder images. However, it is to be understood that it may be employed with equal facility in other In the process of xerography, for example, as disclosed in Carlson Patent 2,297,691, issued October 6, 1942, a xerographic plate, comprising a layer of photo- .conduct-ive insulating material on a conductive backing,

is given a uniform electric charge over its surface and is then exposed to the subject matter to be reproduced, usually by conventional projection techniques. This exposure discharges the plate areas in accordance with the radiation intensity that reaches them, and thereby creates an electrostatic latent image on or in the photoconductive layer. Development of the latent image is effected with an electrostatically charged, finely divided developing material or toner which is brought into surface contact with the photoconductive layer and is held thereon electrostatically in a pattern corresponding to the electrostatic latent image. Thereafter, the developed xerographic powder image is usually transferred to a support surface such as paper to which it may be fixed by any suitable means.

One of the methods in common use for developing the electrostatic latent image is described in Walkup Patent 2,618,551, and is known as cascade development, and is in general use for line copy development. In this technique, the powder or toner is mixed with a granular carrier material, and this two-component developer is poured or cascaded over the plate surface. The function of the'car-rier material is to improve the flow characteristics of the powder and to produce, on the powder, by triboelectrification, the proper electrical charge so that the powder will be attracted to the image. More exactly, the function of the carrier material is to provide the mechanical control to the powder, or to carry the powder to an image surface and, simultaneously, to provide homogeneity of charge polarity.

In the Carlson patent it is noted that a variety of types of finely divided electroscopi-c powders may beemployed for developing electrostatic latent images. However, as the art of xerograph-y has progressed, it has been found preferable to develop line copy images with a powder or toner formed of any of a variety of pigmented thermoplastic resins that have been specifically developed for the purpose. A number of such developing materials are manufactured and marketed commercially and arespecifically compounded for producing dense images of high resolution and to have characteristics to permit convenient storage and handling. Such developing materials ice are compounded to permit them to be fixed to the surface of a transfer material either by heat fixing or vapor fixing techniques, in accordance with the particular application in which they are employed, that is, the individual particles of resin (toner) soften and coalesce when heated or plasticized by solvent, so that they become sticky or tac-kified and readily adhere to the surface of the support material.

The term tackified and the several variant forms thereof used throughout this specification are employed to define the condition of the powder particles of the xerographic powder image when heated or plasticized by a solvent in a manner such that the individual particles soften and coalesce and in which state they become sticky and readily adhere to other surfaces. Although this condition necessarily requires a flowing together of the particles to effect a thorough fusion thereof, it is to be understood that the extent of such flowing is not sufficient to extend beyond the boundary of the pattern in which the particles are formed.

One of the important applications of the process of xerography comprises its use in automatic copying machines for general ofiice use wherein the powder images formed on .a xerographic plate are transferred to paper and then fixed thereon by heat fusing. In order to fuse resinous powder images formed of the powdered resins now commonly used, it is necessary to heat the powder and the paper to which it is to be fused to a relatively high temperature, such as approximately 325 It is undesirable, however, to raise the temperature of the paper substantially higher than 375 F. because of the tendency of paper to discolor at such elevated temperatures.

It has long been recognized that one of the fastest and most positive methods of applying heat for fusing the powder image to paper is to bring the powder image into direct contact with a hot surface, such as a heated fiat,

plate.

But, as the powder image is tackified by heat, part of the image carried by the support material will stick to the surface of the heated plate, so that as the next sheet is placed on the heated plate, the tackified image partially removed from the first sheet will partly transfer to the next sheet and, at the same time, part of the tackified image from said next sheet would adhere to the heated plate. This process is commonly referred to in the printing art as set off or offset, the latter term being'preferred.

The offset of toner onto the heated contacting surface has heretofore led to the rejection of contact fusers in favor of other heat fixing devices, primarily coiled radiant element heaters with reflectors. These radiant element heaters with reflectors have the disadvantage of dissipating a large quantity of heat into the machine enclosure in which they are used, heat transfer to the powder image is inefficient, and they present a safety hazard because of the exposed radiant element.

It is, therefore, the principal object of this invention to improve the construction of a direct contact fusing device for toner images which will rapidly fuse toner images while preventing toner offset.

Another object of this invention. is to improve the construction of a direct contact fusing ,device to attain eflicient :heat transfer to the toner image to be fused.

It is still another object of the invention to improve the construction of a heat fixing device to have low stand-by power requirement.

These and other objects of the invention are attained by means of a direct contact fusing device in which the toner image is fused by forwarding the sheet or web of paper bearing the toner image between two rolls, one of which is heated, the roll contacting the image being provided with a thin coating of a Du Pont Corporation product composed of tetrafluoroethylene resin sold under thetrademark Teflon, and a silicone oil film to prevent toner offset. Both the Teflon and silicone oil have such physical characteristics that they are substantially abhesive to dry or tackified xerographic developing materials. Abhesive is a relatively new term that was coined by Dow Corning Corporation primarily in connection with their silicones to define a surface that has release characteristics such that it is highly repellant to sticky or tacky substances. The word is adopted in this sense herein and is so used throughout the disclosure.

For a better understanding of the invention as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be read in connection with the accompanying drawings wherein:

FIG. 1 illustrates schematically a preferred embodiment of an electrophotographic apparatus adapted for automatic operation, and incorporating a heat fuser constructed in accordance with the invention;

FIG. 2 is a right-hand end view of the heat fuser of the invention;

FIG. 3 is a left-hand end view of the heat fuser;

FIG. 4 is a sectional View taken along line 4-4 of FIG. 2;

FIG. 5 is a sectional view taken along line 55 of FIG. 4;

FIG. 6 is a top view of the heat fuser with parts broken away to show details of the heat fuser; and

FIG. 7 is a view taken along line 7 7 of FIG. 5, with parts broken away to show details of the heat fuser.

Although it forms no part of the subject invention, there is shown schematically in FIG. 1 a continuous Xerographic apparatus for the purpose of illustrating a suitable environment for the heat fuser of the subject invention.

As shown schematically in FIG. 1, the automatic xerographic reproducing apparatus comprises a xerographic plate 20 including a photoconductive layer or light-receiving surface on a conductive backing and formed in the shape of a drum, which is mounted on a shaft journaled in a frame to rotate in the direction indicated by the arrow to cause the drum surface sequentially to pass a plurality of xerographic processing stations.

For the purpose of the present disclosure, the several xerographic processing stations in the path of movement of the drum surface may be described functionally, as follows:

A charging station, at which a uniform electrostatic charge is deposited on the photoconductive layer of the xero graphic drum;

An exposure station, at which a light or radiation pattern of copy to be reproduced is projected onto the drum surface to dissipate the drum charge in the exposed areas thereof and thereby form a latent electrostatic image of the copy to be reproduced;

A developing station, at which a xerographic developing material including toner particles having an electrostatic charge opposite to that of the electrostatic latent image are cascaded over the drum surface, whereby the toner particles adhere to the electrostatic latent image to form a xerographic powdered image in the configuration of the copy being reproduced;

A transfer station, at which the Xerographic powder image is electrostatically transferred from the drum surface to a transfer material or a support surface; and,

A drum cleaning and discharge station, at which the drum surface is brushed to remove residual toner particles remaining thereon after image transfer, and at which the drum surface is exposed to a relatively bright light source to effect substantially complete discharge of any residual electrostatic charge remaining thereon.

The charging station is preferably located as indicated by reference character A. As shown, the charging arrangement includes a corona charging device 21 which includes a corona discharge array of one or more corona discharge electrodes that extend transversely across the drum surface and are energized from a high potential source and are substantially closed within a shielding member.

Next subsequent thereto in the path of motion of the xerographic drum is an exposure station B. An optical scanning or projection system is provided to project a flowing image onto the surface of the photoconductive drum from a stationary original.

The optical scanning or projection assembly comprises a stationary copyboard which consists of a transparent curved platen member 22 such as, for example, a glass plate or the like positioned on the exterior of the cabinet, which is adapted to support a document to be reproduced, the document'being uniformly illuminated and arranged in light projecting relation to the moving light-receiving surface of the xerographic drum. Uniform lighting is provided by banks of lamps LMPS arranged on opposite of the document through a lens 24 onto an image mirror 25 which, in turn, reflects the image onto the xerographic drum through a slot in a fixed light shield 26 positioned adjacent to the xerographic drum surface.

Adjacent to the exposure station is a developing station C in which there is positioned a developer apparatus 30 including a casing or housing having a lower or sump portion for accumulating developer material. A bucket type conveyor is used to carry the developing material to the upper part of the developer housing where it is cascaded over a hopper chute onto the Xerographic drum to effect development. A toner dispenser is used to accurately meter toner to the developing material as toner particles are consumed during the developing operation.

Positioned next and adjacent to the developing station is the image transfer station D which includes .a sheet feeding arrangement adapted to feed sheets of support material, such as paper or the like, successively to the xerographic drum in coordination with the presentation of the developed image on the drum surface at the transfer station.

The sheet feeding mechanism includes a sheet feed device 40 adapted by means of vacuum feeders to feed the top sheet, of a stack of sheets on a tray 41, to a set of feed rollers 42 for advancement by the feed rollers of the sheet to a paper transport 44 which, in turn, conveys the sheet to "a sheet registration device 45 positioned adjacent to the xerographic drum. The sheet registration device arrests and aligns each individual sheet of material and then in timed relation to the movement of the xerographic drum, advances the sheet material into contact with the xerographic drum in registration with a previously formed xerographic powder image on the drum.

The transfer of the xerographic powder image from the drum surface to the sheets of support material is effected by means of a corona transfer device 51 that is located at/ or immediately after the line of contact between the support material and the rotating drum. In operation, the electrostatic field created by the corona transfer device is elfective to tack the support material electrostatically to the drum surface, whereby the support material moves synchronously with the drum while in contact therewith. Simultaneously with the tacking action, the electrostatic field is effective to attract the toner particles comprising the xerographic powder image from the drum surface and cause them to adhere elcctrostatioally to the surface of the support material.

Immediately subsequent to the image transfer station, there is positioned a stripping apparatus or paper pickoif mechanism 52 for removing the sheets of support material from the drum surface. This device, which is of the type disclosed in Rutkus et a1. Patent 3,062,536, includes a plurality of small diameter orifices supplied with pressurized aeriform fluid by a suitable pulsator or other device. The pulsator is adapted to force jets of pressurized aeriform fluid through the outlet orifices into contact with the surface of the xerographic drum slightly in advance of the sheet of support material to strip the leading edge of the sheet from the drum surface and to direct it onto an endless conveyor 55 whereby the sheet material is carried to a fixing device 60. At the fixing device, the transferred xerographic powder image on the sheet of support material is permanently fixed or fused thereto as by heat. After fusing, the finished copy is discharged from the apparatus at a suitable point for collection externally of the apparatus by means of the conveyor 65.

The next and final station in the device is a drum cleaning station E, having positioned therein a corona preclean device 66, similar to corona charging device 21, a drum cleaning device 70 adapted to remove any powder remaining on the xerographic drum after transfer by means of a rotating brush 71, and a discharge lamp LMP-1 adapted to flood the xerographic drum with light to cause dissipation of any residual electrical charge remaining on the xerographic drum.

To remove residual powder from the xerographic drum,

there is disposed a cylindrical brush 7-1 rotatably mounted on an axle and driven by a motor, not'shown. For collecting powder particles removed from the xerographic drum by the brush, there is provided a dust hood 73 that is formed to encompass approximately two-thirds of the brush area. To ensure thorough cleaning of the brush, a flicking bar 74 is secured to the interior of the dust hood adjacent the edge of the outlet duct 75 of the dust hood and in interfering relation with the ends of the brush bristles whereby dust particles may be dislodged therefrom.

For removing dust particles from the brush and dust hood, an exhaust duct 76 is arranged to cover the outlet of thedust hood, the exhaust duct being connected at its other-end to the wall of a filter box 77 attached to the dust hood. A filter bag 78 is secured within the filter box, with the mouth of the filter bag in communication with the exhaust duct. A motor fan unit MOT-6, connected to the filter box, produces 'a flow of air through the filter box drawing air through the area surrounding the xerographic drum and the dust hood, the air entraining powder particles removed from the drum by the brush as the air flows through the dust hood. Powder particles are separated from the air as it flows through the filter bag so that only clean air reaches the motor unit.

Suitable drive means are provided to drive the drum, rotating mirror and sheet feed mechanism at predetermined speeds relative to each other, and to effect operation of the bucket-type conveyor and toner dispenser mechanism.

It is believed that the foregoing description is sufficient for the purposes of this application to show the general operation of the xerographic reproducing apparatus. For further details concerning the specific construction, reference is made to copending Gilbert A. Aser et al. application, filed concurrently herewith and to portions of this specification wherein specific elements cooperating with the sheet feed mechanismare illustrated and described although they form no part of the instant invention.

Referring now to the drawings, there is shown a preferred embodiment of a heated roll fusing device 60 constructed in accordance with the invention.

In the embodiment shown, the heated roller fusing device includes a frame, for supporting the components of the fuser, formed by left-hand plate 801 andright-hand plate 802 secured to the base plate 10.0f the frame for the xerographic apparatus.

Direct contact fusing of a powder image on a support material is achieved by forwarding a sheet of support material bearing the powder image to be fused between a heated upper roller, generally designated 803, and a rubber roller, generally designated 804, rotating in intimate contact under pressure. The support material, carrying the unfused toner images, is advanced between these two rollers with the toner images facing the heated roller so that fusing occurs when contact is made.

Roll 803 includes a cylinder 805 covered with a .suitable material 806 to prevent toner offset onto this roll which contacts the powdered image on the support material. A suitable material may be a coating of a product of tetrafluoroethylene resin sold under the trademark of Teflon by the DuPont Corporatiton. Teflon is a chemically inert, non-porous and non-absorbent, relatively hard and generally form retaining wax-like synthetic resin which is slightly elastic under low stress and which is 'capable of cold flowing under greater stress, and which is capable of sliding over a surface in the manner of self-lubricating relationship therewith.

The cylinder 805 is closed at opposite ends by fuser roll caps 807 and 808, which are secured .to the cylinder. as by a press-fit. A spindle portion of the fuser roll caps are journaled for rotation by bearings 811 mounted in the plates 801 and 802. Bushings 812 extend through the hollow spindle portion of the fuser roll caps. One of the bushings, the left-hand one as seen in FIG. 4, is supported by a bearing retaining cap 813 secured to plate 802'with a thrust washer 814 positioned between the bearing and the retaining cap. The other bushing extends through the hollow spindle portion of fuser roller cap 807 and is secured in position by a set screw 815 in bearing retaining cap 816 secured to plate 801.

Each of the bushings is provided with a suitable aperture to receive a quartz tube 817 which supports a suitable resistance heating element R1. The resistance element R1 is connected by suitable conductors to a source of power such as a commercial 120 volt, 60 cycle alternating current outlet. A thermistor THS-l to control the power to the resistance element R1 is suitably positioned in thermal relation to this fuser roll. For further details concerning the electrical circuit of the fuser in connection with the circuit of the xerographic apparatus of FIG. 1, reference is made to the referenced copending Gilbert A. Aser et al. application.

In the embodiment shown, the fuser 60 is driven in timed relation to the speed of the endless conveyor 55 and the conveyor 65. As shown, the fuser roll cap 808' is provided with a sprocket 821 fixed thereon as by braising. In addition, a gear 822 is secured to the roll cap 808 by screws 823, for a purpose to be described. The endless conveyor 55, fuser 60 and conveyor are oper-atively connected to a common source of power, not shown, by chain belt 701, which in the portion of the drive for the xerographic apparatus shown in FIG. 3, extends from the source of power to engage idler sprocket 707, then up to an idler sprocket 706, down to a drive sprocket 705 used to drive conveyor 65, up and around the sprocket 821 of fuser 60, then the chain belt extends around a sprocket 704 used to drive the endless conveyor 55, from where the chain belt extends back to the into the plates 801 and 802 whereby this assembly is mounted for pivotab'le movement about the axis of the shoulder bolts. The support arms also carry a connecting rod 835 extending therebetween.

The connecting rod is positioned to be contacted by a V-block 841 secured to a diaphragm plate 842 as by screw 843 extending through a washer 844, a diaphragm 845 and the diaphragm plate to threadingly engage the block. The diaphragm 845 is secured over a suitable cavity formed in the base plate 10 by means of a retaining ring 846 held in position by screws 847. The cavity in the base plate 10 is connected by a threaded conduit formed in the base plate, by pipe 8, and conduit 848 to a suitable source of pressure, such as a motor driven compressor (not shown), to effect vertical movement of the diaphragm which through the V-block contacting the connecting rod pivots the supporting arms to force roller 804 into pressure engagement with roll 803 or with a sheet of support material sandwiched therebetween. With this arrangement, the roll 803, when pressure is applied to the diaphragm, is resiliently movable away from roll 803 to permit a support material to enter between these rolls.

The motor driven compressor is suitably connected to the electrical circuit of the xerographic apparatus whereby as the circuit is energized to advance sheets of material through the xerographic apparatus, the motor driving the compressor is energized to supply pressured aeriform fluid to actuate the diaphragm to force roller 804 into contact with roll 803 or a sheet sandwiched therebetween. The contact pressure between rolls 804 and 803 is mechanically controllable by means of adjusting screws 836 threaded through the turned out portions of the support arms, lock nuts 837 being provided to lock these adjusting screws in the desired position. As the roll 804 is raised into contact with roll 803, its upward movement can be limited by contact of these adjusting screws with edge portions of plates 801 and 802. When the xerographic electrical circuit is deenergized or when sheets are not being advanced through the xerographic apparatus, the motor driven compressor is not operated, whereby roll 804 is permitted, due to its Weight and the weight of this entire assembly, to pivot out of contact with roll 803. Thus during standby, when the fuser is not operating, the rollers 803 and 804 are automatically separated. This separation of the lower roller out of contact with the heated roller prevents thermal set of the rubber.

Roll 803 is driven in timed relation wilth roll 884 by means of gear 851 fixed to shaft 825 engaging gear 822 of roll 803.

The pivotable movement of the support arms about the axis of the shoulder bolts is limited by a stop pin 852 extending from plate 801 into interference relation with a support arm, the distance between the center of rolls 804 and 803, if they are moved out of contact with each other, is so limited that gears 822 and 851 will remain in engagement with each other.

As a sheet of support material is advanced between the rolls 803 and 804, the powder image on the support material will contact the peripheral heated surface of roll 803 whereby the powder image becomes tackified and, in this tackified condition, the powder would tend to offset onto this roll except that it is partially prevented from doing so by the Teflon coating on this roll. However, to further prevent even this limited tendency of olfset of powder onto the heated contact surface of roll 803, an applicator is used to supply a thin film of offset preventing liquid, such as silicone oil, to the Teflon coating on roll 803.

A supply of silicone oil to be applied to roll 803 is maintained in an oil pan 861 having fastened, as by welding, to opposite ends thereof brackets 862 and 863 by means of which the oil pan is mounted on the plates 801 and 802. At the left end, as seen in FIGS. 6 and 7, there is provided a spring 864 secured to this end of the pan, for a purpose to be described. An applicator roll, generally designated 871, is used to convey a thin film of oil, as the applicator roll is rotated in the silicon oil to a wick 866, such as a Teflon felt pad secured as by staples, not shown, to a wiper support plate 867 adapted to rest on the peripheral surface of roll 803 and on applicator roll 871. The wiper plate is curved at one end to conform to the peripheral surface of roll 803.

The applicator roll 871 consists of a hollow cylindrical oil drum 872 sealed at opposite ends by caps 873 and 874. Cap 874, on the left end of oil drum 872 as seen in FIGS. 6 and 7, is provided with a concentric button portion adapted to contact spring 864 whereby the applicator roll assembly is movably and rotatably positioned within the oil pan. Cap 873, secured to the opposite end of the oil drum, is provided with a stub shaft portion on which the bushing 875, secured to one end of control arm 876, is journaled, axial alignment being maintained by a snap ring 878 positioned in a suitable annular groove formed near the end of the stub shaft portion of cap 873.

As shown in FIG. 5, the opposite end of control arm 876' is provided with a depending cam surface portion adapted to be engaged by an actuator stud 809 extending outward from roll cap 807 on the upper roller 803. With this arrangement, as the upper roller is rotated through the drive mechanism previously described, the actuator stud 809 will strike the cam surface portion of the control arm to cause the control arm to oscillate about the axis of applicator roll 871 during each revolution of the upper roller 803.

To effect rotation of the applicator roll in one direction, the applicator roll 871 is connected to the bushing 875 secured to the control arm 876 by means of a oneway spring clutch 877. One end of the one-way spring clutch is secured to the cap 873 with the coils of the oneway spring clutch encircling the bushing 875. In this manner, the applicator roll is indexed, a portion of a revolution during each oscillating cycle of the control arm 876 through the one-way spring clutch drive between the applicator roll and the control arm.

To prevent excessive heat loss from roll 803 and roll 804, which is heated by contact with roll 803, there is provided heat baffles 881, 882, 883, each provided with a pad of suitable heat insulating material 884. Both heat bafiles 881 and 882 are provided with guide portions adapted to guide a sheet of support material advanced by endless conveyor 55 into the bite of rolls 803 and 804. V

For a given temperature of the upper roller 803, the fusing rate will depend on the contact arc length of the support material against this roller and the dwell time, i.e., the time the toner image remains between therollers. Dwell time can be varied either by changing the surface velocity of the rollers or by varying the contact arc length and holding the speed of the rollers constant. Contact arc length depends on the softness of the rubber on roller 884 and on the amount of pressure between rollers 803 and804.

In the embodiment of the apparatus shown, the hardness of the rubber used to cover shaft 825, to form roller 804, was in the range of 25 to 65 durometer, and preferably the hardness of the rubber should exceed 40 durometer. By varying the pressure between the rollers, equal contact arc length can be obtained with the different hardness of the rubber.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby, but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed is: v

1. A contact heat fusing device for fixing thermoplastic resin material carried on a support material in image configuration, said device including a frame,

a heated roll journaled in said frame, a pair of support arms pivotally secured to said frame,

a roll journaled in said support arms in parallel relation to said heated roll,

an actuator arm connected to said support arms, actuator means operatively connected to said actuator arm to pivot said support arms from a first position wherein said roll is out of operative relation with said heated roll to a second position wherein said roll is in cooperative relation to said heated roll to forward a support material in pressure contact therebetween,

said actuator means pivoting said roll into cooperative rlationwith said heated roll sufficiently to effect flowirii'of thermoplastic resin material carried on support material in image configuration only within the pattern in which the material is formed,

the peripheral surface of said heated roll having a coating of an offset-preventing material,

means to apply an oiTset preventing liquid to said offset preventing material on said heated roll,

and driving means connected to said heated roll and to 10 said roll to drive said rolls for advancing a support material therebetween. 2. The apparatus of claim 1 in which said actuator means includes a pressure chamber closed at one end by a diaphragm operatively connected to said actuator arm and having at its opposite end conduit means adapted to be connected to a source of pressure.

References Cited by the Examiner UNITED STATES PATENTS EVON C. BLUNK, Primary Examiner. 

1. A CONTACT HEAT FUSING DEVICE FOR FIXING THERMOPLASTIC RESIN MATERIAL CARRIED ON A SUPPORT MATERIAL IN IMAGE CONFIGURATION, SAID DEVICE INCLUDING A FRAME, A HEATED ROLL JOURNALED IN SAID FRAME, A PAIR OF SUPPORT ARMS PIVOTALLY SECURED TO SAID FRAME, A ROLL JOURNALED IN SAID SUPPORT ARMS IN PARALLEL RELATION TO SAID HEATED ROLL, AN ACTUATOR ARM CONNECTED TO SAID SUPPORT ARMS, ACTUATOR MEANS OPERATIVELY CONNECTED TO SAID ACTUATOR ARM TO PIVOT SAID SUPPORT ARMS FROM A FIRST POSITION WHEREIN SAID ROLL IS OUT OF OPERATIVE RELATION WITH SAID HEATED ROLL TO A SECOND POSITION WHEREIN SAID ROLL IS IN COOPERATIVE RELATION TO SAID HEATED ROLL TO FORWARD A SUPPORT MATERIAL IN PRESSURE CONTACT THEREBETWEEN, 